Lotus is pushing to introduce a major upgrade for its car in time for the Monaco Grand Prix, after not getting it ready in time for this weekend’s race in Spain.

Although the Enstone-based team has brought some developments for the Barcelona race, Romain Grosjean revealed on Thursday that there is something bigger being prepared at the factory.

Although he did not elaborate on what it is, it is likely to be a short-nose aerodynamic configuration that a lot of teams have worked on but struggled to get implemented because of tricky crash tests.

"There is a big thing in the pipeline," explained Grosjean.

"We don't have it here but we should have it quite soon. And that will be big – it should make a big difference."

Asked which race he expected it to arrive for, he said: "Monaco or Canada."

Despite not having the full update package yet, Grosjean is convinced that Lotus is making good progress, and can still do well this weekend.

"There are developments in the wind tunnel that are going in the right direction," he said.

"We have some new parts here which should help us, and hopefully a few more ideas coming ideally for the next few races.

"The good thing is that the car has been behaving the same way on very different tracks. It shows if we get the development right it should be a very good step forward."